Electrical insider fitting for internal connection to an electrical box

ABSTRACT

An electrical fitting adapted for insertion from the interior of an electrical box in order to provide a secure means for attaching an electrical cable to the box. The electrical insider fitting includes a connector body having a leading end, a trailing end, and a base flange on the trailing end. A leading face is included on the base flange and a seat on the connector body adjacent the leading face of the base flange. A snap ring resides in the seat and includes one or more outward extending locking tangs. The leading end of the connector body includes an internal bore with an internal snap ring secured therein. The internal snap ring includes one or more cable retaining tangs for engaging and securing an electrical cable to the leading end of the connector body.

This application is a divisional application of U.S. patent applicationSer. No. 14/602,653 filed Jan. 22, 2015 and claims the priority ofProvisional U.S. Patent Application Ser. No. 61/949,620 filed Mar. 7,2014.

FIELD OF THE INVENTION

The present invention relates to electrical boxes and specifically toelectrical fittings for securing electrical cables to electrical boxesand panels.

BACKGROUND OF THE INVENTION

Quick-connect fittings are commonly used to rapidly connect electricalcables with electrical boxes. In a new work situation, in which thedrywall has not yet been installed, electrical cables are pulled to theoutside of the box and the quick-connect fitting is fitted on theelectrical cable and then snapped into the electrical box.

However, in an old work situation, the outside of the electrical box iscovered by the drywall, and, in order to use a conventionalquick-connect fitting, the drywall must be removed and replaced, causingextended time for removing and reinstalling the drywall. Thus,conventional quick-connect fittings cannot be installed from the insideof an electrical box. Furthermore, manual electrical fittings, whichrequire screwdrivers or similar tools to install, are impractical forinstallation from inside the box.

Accordingly, what is needed is an apparatus and method for quicklysecuring an electrical cable from the inside of an electrical boxwithout the use of tools.

BRIEF SUMMARY OF THE INVENTION

The current invention is an electrical fitting adapted for insertionfrom the interior of an electrical box in order to provide a securemeans for attaching an electrical cable to the box. The electricalinsider fitting includes a connector body having a leading end, atrailing end, and a base flange on the trailing end. A leading face isincluded on the base flange and a seat on the connector body adjacentthe leading face of the base flange. A snap ring resides in the seat andincludes one or more outward extending locking tangs. The leading end ofthe connector body includes an internal bore with an internal snap ringsecured therein. The internal snap ring includes one or more cableretaining tangs for engaging and securing an electrical cable to theleading end of the connector body.

OBJECTS AND ADVANTAGES

A first object of the current invention is to provide an electricalfitting that can be easily inserted from the interior of an electricalbox in order to secure an electrical cable to the box.

A second object is to enable an installer to secure an electrical cableto an existing electrical box while avoiding having to remove drywallfrom the outside of the box. Conventional electrical fittings, both themanual and quick-connect type, are typically installed from the exteriorof the box and therefore require the installer to first clear the areasurrounding the box in order to install the conventional fittingEliminating the need to remove and replace drywall substantially reducesthe time and expense required to connect an electrical cable to an oldwork box.

A further object is to provide an apparatus and method to enable rapidconnection of an electrical cable from the inside of an electrical boxwithout the use of tools.

Another object is to provide an electrical fitting that secures to theinner surface an electrical box while taking up very little of theinterior volume of the electrical box.

A further object is to provide an electrical insider fitting in whichthe portion inside the electrical box projects a minimal distance intothe interior volume of the box.

These and other objects and advantages of the present invention will bebetter understood by reading the following description along withreference to the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Reference is made herein to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 is an exploded isometric view of an electrical insider fitting inaccordance with embodiments of the invention.

FIG. 2 is a side view of a connector body which forms a portion of theelectrical insider fitting of FIG. 1.

FIG. 3 is a sectional view of the connector body taken along line 3-3 ofFIG. 2.

FIG. 4 is a sectional view of the connector body taken along line 4-4 ofFIG. 2.

FIG. 5 is a sectional view of the electrical insider fitting assemblyincluding the connector body with the external snap ring, internal snapring, and throat liner.

FIG. 6 is an end view of the assembled electrical insider fitting takenfrom the right side of FIG. 5.

FIG. 7 is a front isometric view of the assembled electrical insiderfitting.

FIG. 8 is a rear isometric view of the assembled electrical insiderfitting.

FIG. 9 is a sectional view of the electrical insider fitting includingan electrical cable in alignment with the fitting to be insertedtherein.

FIG. 10 is an isometric view of a snap ring that forms a portion of theelectrical insider fitting of FIG. 1.

FIG. 11 is an isometric view of an internal snap ring that forms aportion of the electrical insider fitting of FIG. 1.

FIG. 12 is an isometric view of an optional throat liner that forms aportion of the electrical insider fitting of FIG. 1.

FIG. 13 is a sectional view of the electrical insider fitting depictingan electrical cable fully inserted and locked into the fitting assembly.

DETAILED DESCRIPTION

With reference to FIG. 1, the present invention comprises an electricalinsider fitting 20 for connecting an electrical cable to an electricalbox. The electrical insider fitting 20 includes a connector body 22, anexternal snap ring 24, an internal snap ring 26, and an optional throatliner 28.

Referring to FIGS. 2 and 3, the connector body 22 includes a leading end30, a trailing end 32, and a base flange 34 on the trailing end 32. Asused herein, the term “leading end” 30 refers to the end of the fittingwhich is first advanced into the electrical box as it is securedthereto, and the term “trailing end” 32 refers to the end of the fittingthat is opposed to the leading end. In the electrical fitting of thepresent invention, after insertion into the box, the leading end 30resides outside the electrical box and the trailing end 32 residesinside the electrical box. The base flange 34 includes a leading face 33and a trailing face 35. A portion of the connector body 22 isnecked-down on the trailing end 32 adjacent the base flange 34 to form areduced-diameter seat 36. The connector body 22 includes a flangelessmain body portion 37 of a constant diameter extending from the seat 36to the leading end 30 of the connector body. Main body portion 37 isflangeless as there are no flanges extending outward therefrom tointerfere with the insertion of the main body portion 37 of theconnector body 22 through a knock out aperture (not shown) in anelectrical box. The main body portion 37 has a smaller diameter than thebase flange 34 of the connector body 22. A nose portion 38 extendsoutward of the base flange 34 on the trailing end 32. The connectorincludes a trailing end portion 40 and a wider main body portion 37 withan opening 42 therein. As shown in FIG. 2, the outer diameter D5 of theseat 36 is preferably smaller than the outer diameter D6 of the mainbody portion 37 of the connector body 22.

As shown in FIG. 3, the base flange 34 includes a truncated portion 44thereon. Most preferably, there are two openings 42 a and 42 b in themain body portion 37, which openings are preferably not coaxial with oneanother. A bore 46 extends through the substantially tubular connectorbody 22 and the openings are communicative with the bore.

With reference to FIG. 4, the trailing end 32 of the connector body 22includes a flange projection 47 that projects from the flange 34 andforms an inner seat 48 that is adapted to receive the optional throatliner. The inner seat 48 includes an outer recess 50, a lip 52, and abeveled inlet 54. The bore 46 includes a leading bore 56 in the mainbody portion 37 and a trailing bore 58 in the trailing end portion 40.The leading bore 56 includes a larger inside diameter D1 than the insidediameter D2 of the trailing bore 58. Stop 57 is formed at the transitionof the leading bore and trailing bore. Stop 57 is the transition on theinterior of connector body 22 from the larger diameter leading bore 56to the smaller diameter trailing bore 58. The stop 57 functions to limitthe distance of insertion of the internal snap ring 26 into the leadingbore 56 of the connector body 22 (see FIG. 5). Opening 42 a is offsetfrom leading end 30 by distance D3 and opening 42 b is offset fromleading end by distance D4. Most preferably the openings are offset bydifferent distances from the leading end 30.

With reference to FIG. 10, the external snap ring 24 is a split ringthat includes a split 60, a leading end 62, a trailing end 64, and oneor more locking tangs 66 bent outward from the split ring. The lockingtangs 66 include a cantilevered end 68 and a free end 70. Free end 70 isoriented toward the trailing end 64 of the snap ring. The split 60between the two ends of the external snap ring 24 enable the split ringto expand when force is applied to urge the ring to a wider diameter.

As shown in FIG. 11, internal snap ring 26 includes a leading end 72, atrailing end 74, and a split 76 therein. The internal snap ring 26includes a gap 78 at the split to enable the internal snap ring tocompress when force is applied to urge the ring to a smaller diameter.The internal snap ring 26 further includes locking tangs 80 that arebent outward of the ring and cable retaining tangs 82 that are bentinward of the ring. Locking tangs 80 include free ends 84 that areoriented toward the leading end 72 and cable retaining tangs 82 includefree ends 86 that are oriented toward the trailing end 74 of theinternal snap ring 26.

Referring to FIG. 12, throat liner 28 includes a leading end 88, atrailing end 90, a nose portion 92, and a flange 94.

Referring to FIG. 5, the electrical insider fitting 20 assembly includesthe connector body 22, external snap ring 24, internal snap ring 26, andthe optional throat liner 28.

With reference to FIG. 6, the electrical insider fitting 20 mostpreferably includes three of the cable retaining tangs 82 extending fromthe internal snap ring 26 including a middle tang 82 a and two sidetangs 82 a. Each of the cable retaining tangs includes a base portion96, an end portion 98 that is bent away from the base portion, and afree end 86. The middle tang 82 a includes an edge 103 that isperpendicular to the sides 105 of the tang and the two side tangs 82 ainclude edges 107 that are angled with respect to the sides. Thetruncated portion 44 of the base flange 34 enables the fitting 20 to beinserted within a knockout that is in close proximity to the wall of theelectrical box.

Referring to FIGS. 7 and 8, the assembled electrical insider fitting 20includes the external snap ring 24 disposed on the reduced-diameter seat36 on the trailing end 32 of the connector body 22. The optional throatliner 28, if used for a particular application, is pressed into thetrailing bore 58 in the fitting. The optional throat liner 28 preventsabrasion of the wiring extending through the trailing end of theconnector. Preferably, the throat liner 28 is constructed of a resilientelectrically non-conductive material, such as plastic or rubber. Mostpreferably, the throat liner is constructed of plastic.

As shown in FIG. 7, the internal snap ring 26, being a split ringpreferably constructed of a resilient metal, is compressed slightly andeasily inserted within the leading bore 56 of the fitting. The internalsnap ring 26 then expands to the full inner diameter of leading bore 56and provides a tight fit of the internal snap ring within the connectorbody 22. Locking tangs 80 of internal snap ring 26 extend through theopenings 42 and, in conjunction with openings 42 a and 42 b of connectorbody 22, provide a means of aligning the internal snap ring within theleading bore 56 in the leading end 30 of the connector body 22.

Referring to FIG. 8, external snap ring 24, also preferably constructedof a resilient metal, is expanded slightly and slipped onto the seat 36of connector body 22, where it relaxes to its original smaller diameterand thereby is retained on the seat 36. Assembled connector body 22,external snap ring 24, and internal snap ring 26 form the electricalinsider fitting 20.

Reference is made to FIG. 9 for an understanding of the operation of thepresent invention. Although the electrical insider fitting 20 can beused in both new work and old work situations, it is most useful on oldwork electrical boxes where the drywall is already installed around theelectrical box. The electrical insider fitting 20 enables an installerto pull electrical cable 113 into the existing box 115 and then use theinsider fitting to secure the electrical cable to the box without havingto remove drywall, which would be covering the outside 117 of theelectrical box. The advantage of the electrical insider fitting 20 isthat it can be installed from inside 119 the electrical box 115, therebyenabling the installer to avoid the substantial time required to removeand replace the drywall in order to secure the electrical cable to thebox. The free end 70 of the locking tang 66 of the external snap ring 24and the free end 84 of the cable retaining tang 82 of the internal snapring 26 are oriented toward, or directed to, the trailing end 32 of theconnector body 22. The free end 70 of the locking tang 66 of theexternal snap ring 24 and the free end 84 of the locking tang 80 of theinternal snap ring 26 are oriented toward opposing ends of the connectorbody 22.

To operate the invention, from inside 119 the box, the leading end 30 ofelectrical insider fitting 20 is simply pressed through an existingknock-out hole 121 in the electrical box 115. The locking tangs 66 ofexternal snap ring 24 are biased inwardly as the pass through theelectrical box walls 123. As shown in FIG. 13, after clearing the walls123 of the electrical box 115, the locking tangs 66 of external snapring 24 snap outwardly and lock the fitting 20 to the electrical box115. Electrical cable 113 is then inserted through internal bore 46 offitting 20 until the cable is grasped by free ends 84 of cable retainingtangs 82. The free ends 84 of cable retaining tangs 82 lock theelectrical cable 113 to the electrical box wall 123. As shown in FIG. 9,after being installed to the inside surface 119 of the electrical box115, very little of the electrical insider fitting 20 projects into theinterior volume of the electrical box. Only the flange 34 and a smallportion of the throat liner 28 project into the interior volume of thebox. As the throat liner 28 is optional, with omission of the throatliner, the only portion that will project into the interior volume isthe flange 34, which preferably includes a maximum thickness of 0.10inch. Thus, for those embodiments without a throat liner, the flangeprojection 47 of the connector body 22, as shown in FIG. 4, can beeliminated so that only the flange 34 extends within the interior volumeof the box.

External snap ring 24 and internal snap ring 26 are most preferablyconstructed of spring steel. Connector body 22 most preferably isdie-cast of metal. As shown in FIG. 9, the electrical insider fitting 20provides good electrical continuity between the outer sheath of theelectrical cable 113, the electrical box 115 and the fitting 20 itselfincluding the external snap ring 24, the internal snap ring 26, and theconnector body 22. A grounding path is established between theelectrical box 115 and the connector body 22 by the flush contact ofbase flange 34 with the electrical box wall 123 and by the locking tangsin contact with the outside 117 of the electrical box wall. The lockingtangs 66, being constructed of resilient metal, remain biased againstthe outside surface 117 of the box and thereby keep base flange 34pressed tight against the box. At the same time, the tight fit ofinternal snap ring 26 within the connector body 22 keeps the internalsnap ring locked within the leading end 30 of the connector body 22.Upon cable insertion, cable retaining tangs 82 tightly grasp theelectrical cable 113, and the internal snap ring 26 maintains a biasagainst the internal walls of the connector body 22. Thus electricalcontinuity is established and maintained between the electrical cable113, the electrical box 115, and the electrical insider fitting 20.Locking tangs 80 further assist in maintaining electrical continuitybetween the cable 113, the internal snap ring 26 and the connector body22.

With reference to FIGS. 9 and 13, the present invention includes amethod of securing an electrical fitting 20 to an electrical box 115having a wall 123 with an inside surface 119 and a knockout aperture 121therein, the method including 1) providing an electrical fitting 20including a connector body 22 having a leading end 30, a trailing end32, a main body portion 37 having a bore 46 therein including a leadingbore 56 and a trailing bore 58, a base flange 34 on the trailing end 32of the connector body 22, a leading face 33 on the base flange 34, areduced-diameter seat 36 on the trailing end 32 of the connector body,an external snap ring 24 disposed on the seat 36 of the connector body,locking tangs 66 on the external snap ring 24, an internal snap ring 26within the leading bore 56, and cable retaining tangs 82 on the internalsnap ring 26; 2) inserting the leading end 30 of the connector body 22into the knockout aperture 121 until the leading face 33 of the baseflange 34 is flush with the inside surface 119 of the electrical box 115and the locking tangs 66 of the snap ring 24 snap clear the wall 123 ofthe electrical box 115; and 3) inserting an electrical cable 113 intothe bore 46 of the connector body until the cable retaining tangs 82snap into the electrical cable and lock the electrical cable within theconnector body 22.

With reference to FIG. 1, the connector body 22 is preferably die castof zinc alloy in one-piece. The snap ring 24 and internal snap ring 26are each preferably formed in one-piece of resilient spring steel.External snap ring 24 is a split ring that is preferably formed to asmaller diameter than the seat 36 on the trailing end 32 of theconnector body 22. Thus, external snap ring 24 may be forcefullyexpanded and pressed over the leading end 30 of connector body untilsnapping onto the seat 36 at the trailing end 32 of the connector body.The external snap ring 24 is held onto the seat 36 by its resilientnature and tendency to spring back to its unbiased diameter.

Internal snap ring 26 is a split ring preferably formed to a largerdiameter than the bore 46 in the leading end 30 of the connector body.As shown in FIG. 10, the internal snap ring 26 includes a cutout 120 onone end of the split 60 and a tongue 124 on the opposing side of thesplit 60. The split 60 permits slight compression of the internal snapring 26 and thus easy insertion into the connector body 22 to form theelectrical insider fitting 20 (see FIG. 1). Once the internal snap ring26 expands to the full inner diameter of the die-cast connector bodybore 26, a tight fit is formed of the internal snap ring within theconnector body. Each locking tang 80 is offset from the leading end 62of the internal snap ring 26 by a distance corresponding to one of theopenings 42 a and 42 b in the connector body 22. The locking tangs 80 ofthe internal snap ring 26 in conjunction with the openings 42 inconnector body provide an aligning arrangement 125 for aligning theinternal snap ring 26 in the desired orientation within the connectorbody 22.

The description of the present invention has been presented for purposesof illustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. An electrical fitting for connecting anelectrical cable to an electrical box having a wall, comprising: aconnector body having a leading end including a main body portion with aleading bore for insertion through an access hole in the electrical box,and a trailing end with a trailing bore; a base flange on said trailingend of said connector body, said base flange including a leading face; areduced-diameter seat on said trailing end of said connector body, saidseat extending from said leading face of said base flange to said mainbody portion; an external snap ring disposed on said seat of saidconnector body, said external snap ring including a locking tang havinga free end; an internal snap ring disposed within said leading bore ofsaid connector body, said internal snap ring including a cable retainingtang; and said free end of said locking tang of said external snap ringand said free end of said cable retaining tang of said internal snapring are oriented toward the trailing end of said connector body.
 2. Theelectrical fitting of claim 1, including a retaining arrangement forretaining said internal snap ring within said leading bore of saidconnector body.
 3. The electrical fitting of claim 2, wherein saidretaining arrangement includes an opening in said connector body; and alocking tang extending outward from said internal snap ring and throughsaid opening.
 4. The electrical fitting of claim 1, including an innerwall on said connector body; and a stop on said inner wall of saidconnector body at the juncture of said leading bore and said trailingbore.
 5. The electrical fitting of claim 1 wherein said base flange isof a larger diameter than the diameter of said main body portion of saidconnector body.
 6. The electrical fitting of claim 1 further comprisinga trailing face and a leading face on said base flange.
 7. Theelectrical fitting of claim 1 wherein said leading face of said baseflange and said free end of said locking tang of said external snap ringlock engage opposing sides of said electrical box wall.
 8. Theelectrical fitting of claim 1 wherein engagement of said leading face ofsaid base flange and said free end of said locking tang of said externalsnap ring lock said trailing end of said connector body to saidelectrical box.
 9. The electrical fitting of claim 1 wherein said freeend of said locking tang of said external snap ring and said free end ofsaid cable retaining tang of said internal snap ring are oriented towardthe trailing end of the connector body.
 10. The electrical fitting ofclaim 1 wherein said free end of said locking tang of said external snapring and said cable retaining tang of said locking tang of said internalsnap ring are oriented toward the same end of the connector body. 11.The electrical fitting of claim 1 wherein said free end of said lockingtang of said external snap ring and said free end of said locking tangof said internal snap ring are oriented toward opposing ends of theconnector body.